arch/microblaze/kernel/timer.c

   1 /*
   2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2007-2009 PetaLogix
   4  * Copyright (C) 2006 Atmark Techno, Inc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License. See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/param.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/profile.h>
  16 #include <linux/irq.h>
  17 #include <linux/delay.h>
  18 #include <linux/sched.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/err.h>
  21 #include <linux/clk.h>
  22 #include <linux/clocksource.h>
  23 #include <linux/clockchips.h>
  24 #include <linux/io.h>
  25 #include <linux/bug.h>
  26 #include <asm/cpuinfo.h>
  27 #include <asm/setup.h>
  28 #include <asm/prom.h>
  29 #include <asm/irq.h>
  30 #include <asm/system.h>
  31 #include <linux/cnt32_to_63.h>
  32
  33 #ifdef CONFIG_SELFMOD_TIMER
  34 #include <asm/selfmod.h>
  35 #define TIMER_BASE      BARRIER_BASE_ADDR
  36 #else
  37 static unsigned int timer_baseaddr;
  38 #define TIMER_BASE      timer_baseaddr
  39 #endif
  40
  41 static unsigned int freq_div_hz;
  42 static unsigned int timer_clock_freq;
  43
  44 #define TCSR0   (0x00)
  45 #define TLR0    (0x04)
  46 #define TCR0    (0x08)
  47 #define TCSR1   (0x10)
  48 #define TLR1    (0x14)
  49 #define TCR1    (0x18)
  50
  51 #define TCSR_MDT        (1<<0)
  52 #define TCSR_UDT        (1<<1)
  53 #define TCSR_GENT       (1<<2)
  54 #define TCSR_CAPT       (1<<3)
  55 #define TCSR_ARHT       (1<<4)
  56 #define TCSR_LOAD       (1<<5)
  57 #define TCSR_ENIT       (1<<6)
  58 #define TCSR_ENT        (1<<7)
  59 #define TCSR_TINT       (1<<8)
  60 #define TCSR_PWMA       (1<<9)
  61 #define TCSR_ENALL      (1<<10)
  62
  63 static inline void microblaze_timer0_stop(void)
  64 {
  65         out_be32(TIMER_BASE + TCSR0, in_be32(TIMER_BASE + TCSR0) & ~TCSR_ENT);
  66 }
  67
  68 static inline void microblaze_timer0_start_periodic(unsigned long load_val)
  69 {
  70         if (!load_val)
  71                 load_val = 1;
  72         out_be32(TIMER_BASE + TLR0, load_val); /* loading value to timer reg */
  73
  74         /* load the initial value */
  75         out_be32(TIMER_BASE + TCSR0, TCSR_LOAD);
  76
  77         /* see timer data sheet for detail
  78          * !ENALL - don't enable 'em all
  79          * !PWMA - disable pwm
  80          * TINT - clear interrupt status
  81          * ENT- enable timer itself
  82          * EINT - enable interrupt
  83          * !LOAD - clear the bit to let go
  84          * ARHT - auto reload
  85          * !CAPT - no external trigger
  86          * !GENT - no external signal
  87          * UDT - set the timer as down counter
  88          * !MDT0 - generate mode
  89          */
  90         out_be32(TIMER_BASE + TCSR0,
  91                         TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT);
  92 }
  93
  94 static inline void microblaze_timer0_start_oneshot(unsigned long load_val)
  95 {
  96         if (!load_val)
  97                 load_val = 1;
  98         out_be32(TIMER_BASE + TLR0, load_val); /* loading value to timer reg */
  99
 100         /* load the initial value */
 101         out_be32(TIMER_BASE + TCSR0, TCSR_LOAD);
 102
 103         out_be32(TIMER_BASE + TCSR0,
 104                         TCSR_TINT|TCSR_ENIT|TCSR_ENT|TCSR_ARHT|TCSR_UDT);
 105 }
 106
 107 static int microblaze_timer_set_next_event(unsigned long delta,
 108                                         struct clock_event_device *dev)
 109 {
 110         pr_debug("%s: next event, delta %x\n", __func__, (u32)delta);
 111         microblaze_timer0_start_oneshot(delta);
 112         return 0;
 113 }
 114
 115 static void microblaze_timer_set_mode(enum clock_event_mode mode,
 116                                 struct clock_event_device *evt)
 117 {
 118         switch (mode) {
 119         case CLOCK_EVT_MODE_PERIODIC:
 120                 printk(KERN_INFO "%s: periodic\n", __func__);
 121                 microblaze_timer0_start_periodic(freq_div_hz);
 122                 break;
 123         case CLOCK_EVT_MODE_ONESHOT:
 124                 printk(KERN_INFO "%s: oneshot\n", __func__);
 125                 break;
 126         case CLOCK_EVT_MODE_UNUSED:
 127                 printk(KERN_INFO "%s: unused\n", __func__);
 128                 break;
 129         case CLOCK_EVT_MODE_SHUTDOWN:
 130                 printk(KERN_INFO "%s: shutdown\n", __func__);
 131                 microblaze_timer0_stop();
 132                 break;
 133         case CLOCK_EVT_MODE_RESUME:
 134                 printk(KERN_INFO "%s: resume\n", __func__);
 135                 break;
 136         }
 137 }
 138
 139 static struct clock_event_device clockevent_microblaze_timer = {
 140         .name           = "microblaze_clockevent",
 141         .features       = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
 142         .shift          = 8,
 143         .rating         = 300,
 144         .set_next_event = microblaze_timer_set_next_event,
 145         .set_mode       = microblaze_timer_set_mode,
 146 };
 147
 148 static inline void timer_ack(void)
 149 {
 150         out_be32(TIMER_BASE + TCSR0, in_be32(TIMER_BASE + TCSR0));
 151 }
 152
 153 static irqreturn_t timer_interrupt(int irq, void *dev_id)
 154 {
 155         struct clock_event_device *evt = &clockevent_microblaze_timer;
 156 #ifdef CONFIG_HEART_BEAT
 157         heartbeat();
 158 #endif
 159         timer_ack();
 160         evt->event_handler(evt);
 161         return IRQ_HANDLED;
 162 }
 163
 164 static struct irqaction timer_irqaction = {
 165         .handler = timer_interrupt,
 166         .flags = IRQF_DISABLED | IRQF_TIMER,
 167         .name = "timer",
 168         .dev_id = &clockevent_microblaze_timer,
 169 };
 170
 171 static __init void microblaze_clockevent_init(void)
 172 {
 173         clockevent_microblaze_timer.mult =
 174                 div_sc(timer_clock_freq, NSEC_PER_SEC,
 175                                 clockevent_microblaze_timer.shift);
 176         clockevent_microblaze_timer.max_delta_ns =
 177                 clockevent_delta2ns((u32)~0, &clockevent_microblaze_timer);
 178         clockevent_microblaze_timer.min_delta_ns =
 179                 clockevent_delta2ns(1, &clockevent_microblaze_timer);
 180         clockevent_microblaze_timer.cpumask = cpumask_of(0);
 181         clockevents_register_device(&clockevent_microblaze_timer);
 182 }
 183
 184 static cycle_t microblaze_read(struct clocksource *cs)
 185 {
 186         /* reading actual value of timer 1 */
 187         return (cycle_t) (in_be32(TIMER_BASE + TCR1));
 188 }
 189
 190 static struct timecounter microblaze_tc = {
 191         .cc = NULL,
 192 };
 193
 194 static cycle_t microblaze_cc_read(const struct cyclecounter *cc)
 195 {
 196         return microblaze_read(NULL);
 197 }
 198
 199 static struct cyclecounter microblaze_cc = {
 200         .read = microblaze_cc_read,
 201         .mask = CLOCKSOURCE_MASK(32),
 202         .shift = 8,
 203 };
 204
 205 static int __init init_microblaze_timecounter(void)
 206 {
 207         microblaze_cc.mult = div_sc(timer_clock_freq, NSEC_PER_SEC,
 208                                 microblaze_cc.shift);
 209
 210         timecounter_init(&microblaze_tc, &microblaze_cc, sched_clock());
 211
 212         return 0;
 213 }
 214
 215 static struct clocksource clocksource_microblaze = {
 216         .name           = "microblaze_clocksource",
 217         .rating         = 300,
 218         .read           = microblaze_read,
 219         .mask           = CLOCKSOURCE_MASK(32),
 220         .shift          = 8, /* I can shift it */
 221         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 222 };
 223
 224 static int __init microblaze_clocksource_init(void)
 225 {
 226         clocksource_microblaze.mult =
 227                         clocksource_hz2mult(timer_clock_freq,
 228                                                 clocksource_microblaze.shift);
 229         if (clocksource_register(&clocksource_microblaze))
 230                 panic("failed to register clocksource");
 231
 232         /* stop timer1 */
 233         out_be32(TIMER_BASE + TCSR1, in_be32(TIMER_BASE + TCSR1) & ~TCSR_ENT);
 234         /* start timer1 - up counting without interrupt */
 235         out_be32(TIMER_BASE + TCSR1, TCSR_TINT|TCSR_ENT|TCSR_ARHT);
 236
 237         /* register timecounter - for ftrace support */
 238         init_microblaze_timecounter();
 239         return 0;
 240 }
 241
 242 /*
 243  * We have to protect accesses before timer initialization
 244  * and return 0 for sched_clock function below.
 245  */
 246 static int timer_initialized;
 247
 248 void __init time_init(void)
 249 {
 250         u32 irq, i = 0;
 251         u32 timer_num = 1;
 252         struct device_node *timer = NULL;
 253         const void *prop;
 254 #ifdef CONFIG_SELFMOD_TIMER
 255         unsigned int timer_baseaddr = 0;
 256         int arr_func[] = {
 257                                 (int)&microblaze_read,
 258                                 (int)&timer_interrupt,
 259                                 (int)&microblaze_clocksource_init,
 260                                 (int)&microblaze_timer_set_mode,
 261                                 (int)&microblaze_timer_set_next_event,
 262                                 0
 263                         };
 264 #endif
 265         const char * const timer_list[] = {
 266                 "xlnx,xps-timer-1.00.a",
 267                 NULL
 268         };
 269
 270         for (i = 0; timer_list[i] != NULL; i++) {
 271                 timer = of_find_compatible_node(NULL, NULL, timer_list[i]);
 272                 if (timer)
 273                         break;
 274         }
 275         BUG_ON(!timer);
 276
 277         timer_baseaddr = be32_to_cpup(of_get_property(timer, "reg", NULL));
 278         timer_baseaddr = (unsigned long) ioremap(timer_baseaddr, PAGE_SIZE);
 279         irq = be32_to_cpup(of_get_property(timer, "interrupts", NULL));
 280         timer_num = be32_to_cpup(of_get_property(timer,
 281                                                 "xlnx,one-timer-only", NULL));
 282         if (timer_num) {
 283                 eprintk(KERN_EMERG "Please enable two timers in HW\n");
 284                 BUG();
 285         }
 286
 287 #ifdef CONFIG_SELFMOD_TIMER
 288         selfmod_function((int *) arr_func, timer_baseaddr);
 289 #endif
 290         printk(KERN_INFO "%s #0 at 0x%08x, irq=%d\n",
 291                 timer_list[i], timer_baseaddr, irq);
 292
 293         /* If there is clock-frequency property than use it */
 294         prop = of_get_property(timer, "clock-frequency", NULL);
 295         if (prop)
 296                 timer_clock_freq = be32_to_cpup(prop);
 297         else
 298                 timer_clock_freq = cpuinfo.cpu_clock_freq;
 299
 300         freq_div_hz = timer_clock_freq / HZ;
 301
 302         setup_irq(irq, &timer_irqaction);
 303 #ifdef CONFIG_HEART_BEAT
 304         setup_heartbeat();
 305 #endif
 306         microblaze_clocksource_init();
 307         microblaze_clockevent_init();
 308         timer_initialized = 1;
 309 }
 310
 311 unsigned long long notrace sched_clock(void)
 312 {
 313         if (timer_initialized) {
 314                 struct clocksource *cs = &clocksource_microblaze;
 315                 cycle_t cyc = cnt32_to_63(cs->read(NULL));
 316                 return clocksource_cyc2ns(cyc, cs->mult, cs->shift);
 317         }
 318         return 0;
 319 }